When you think about perms, various images may come to mind; maybe the hair styles of the 80’s, or Carrie Bradshaw’s infamous curls. Perms are a popular cosmetic treatment that transforms straight hair into curls or waves. This transformation relies on breaking and reforming the disulfide bonds in keratin, the protein that gives hair its structure. Traditionally, harsh chemicals like ammonium thioglycolate have been used for this process, but they often result in significant hair damage and scalp irritation. Sodium borohydride (NaBH4), however, is emerging as a revolutionary alternative, offering a gentler and more effective solution for hair perming.
The Chemistry of Traditional Hair Perms
The perming process involves three main stages:
1. Reduction Phase:
- Traditional Reducing Agents: Ammonium thioglycolate is commonly used to break the disulfide bonds in keratin. This process makes the hair pliable and ready to be reshaped.
- Chemical Reaction:
R–S–S–R + HS–CH2COOH -> 2 R–SH + CH2(COO)
In this reaction, the disulfide bonds (R–S–S–R) in keratin are reduced to two thiol groups (R–SH), allowing the hair to be reshaped around perm rods.
2. Reshaping:
- Curl Formation: The hair, now flexible, is wrapped around perm rods to form curls or waves. The reducing agent remains on the hair for a set period to ensure the bonds remain broken.
3. Oxidation Phase:
Oxidizing Agents: Hydrogen peroxide or sodium bromate is applied to reform the disulfide bonds in their new configuration.
Chemical Reaction:
2 R–SH + H2O2 -> R–S–S–R + 2 H2O
This re-forms the disulfide bonds, locking the hair into its new shape.
The Alternative: Borohydride in Hair Perms
Borohydride salts present a modern alternative to traditional perm chemicals. As a reducing agent, it effectively breaks disulfide bonds but operates under milder conditions, reducing the risk of hair damage and scalp irritation.
How Borohydrides Work
1. Reduction Phase:
Application: Sodium borohydride is applied to the hair to break the disulfide bonds in keratin.
Chemical Reaction:
-RSSR- + 2 NaBH4 -> 2 -RSH + 2 NaBO2
In this reaction, sodium borohydride reduces the disulfide bonds to thiol groups, with sodium metaborate and hydrogen gas as byproducts.
Other borohydrides, such as tetraammonium salts, and sodium triacetoxyborohydride are also effective, offering formulation flexibility.
2. Reshaping:
- The hair, now softened, is wrapped around perm rods to create the desired curl pattern.
3. Oxidation Phase:
- Application of Oxidizing Agent: Hydrogen peroxide or a similar agent is used to reform the disulfide bonds in their new positions.
- Chemical Reaction:
2 R–SH + H2O2 -> R–S–S–R + 2 H2O
This re-forms the disulfide bonds, locking the hair into its new shape.
Benefits of Borohydride in Hair Perms
1. Gentler on Hair: Borohydride salts are less harsh than traditional reducing agents, effectively breaking disulfide bonds without causing significant hair damage. This results in healthier, stronger hair with reduced risk of breakage and split ends.
2. Minimized Scalp Irritation: The mild nature of sodium borohydride minimizes the risk of scalp irritation and allergic reactions, making the perming process more comfortable for users, especially those with sensitive skin.
3. Improved Curl Quality: Sodium borohydride allows for more controlled breaking and reforming of disulfide bonds, resulting in better-defined and longer-lasting curls or waves. The curls are often more natural-looking and less frizzy.
4. Pleasant Experience: Unlike traditional perming agents that have a strong, unpleasant odor, sodium borohydride produces significantly less odor, making the perming experience more pleasant for both the stylist and the client.
5. Environmental and Health Benefits: Borohydride has a lower environmental impact compared to traditional perming chemicals. It decomposes into relatively benign byproducts, reducing potential harm to both users and the environment.
Borohydride offers a gentler, more effective alternative to traditional reducing agents. By minimizing hair damage and scalp irritation, enhancing curl quality, and providing a more pleasant experience, sodium borohydride could set a new standard in haircare.
If you want to learn more about potential uses and benefits of Sodium Borohydride, reach out to [email protected].